Cristobal to unleash rare tropical high winds, heavy rain over Midwest

Cristobal pushed northward across the Upper Midwest on Wednesday morning, three days after thrashing the Gulf Coast. The was downgraded to a tropical rainstorm on Tuesday evening. Torrential rainfall continued to fall along Cristobal's path -- and all told, Cristobal could travel 2,000 miles from where it originated in the southwestern Gulf of Mexico to where it is heading in the Midwest.

Even though the system has weakened to a tropical rainstorm, it will join forces with a non-tropical storm, and the duo is projected to unleash strong winds and soaking rain across parts of the Midwest.

After some weakening of Cristobal in terms of central barometric pressure into Tuesday morning, a gain in strength is forecast as the system spins across the Great Lakes region and into Canada on Wednesday.

"At landfall, Cristobal had a central pressure of 29.29 inches of mercury Sunday evening but could end up close to 29.00 inches of mercury over the northern Great Lakes and Ontario at midweek," Paul Walker, an AccuWeather forecaster, said.

How low the barometric pressure is in a storm, whether tropical in nature or not, is a good indicator as to its intensity, especially in terms of the winds it can produce.

Meanwhile, strong wind gusts from a non-tropical feature are forecast to rip across parts of the Plains into Tuesday night prior to that system meeting up with Cristobal.

Winds gusted past 70 mph in parts of eastern Colorado on Tuesday. Gusty winds kicked up a considerable amount of dust over the southern Plains as well.

Into Wednesday, winds will ramp up around the Great Lakes region as the non-tropical system and Cristobal merge.

Winds gusted to 53 mph at Champaign and Decatur, Illinois, during Tuesday morning as the circulation from Cristobal passed to the west. Winds gusted to 49 mph at Terre Haute, Indiana.

"Wind gusts may end up being stronger around the Great Lakes at midweek than they were along much of the Gulf coast this past weekend," Dan Kottlowski, AccuWeather's top hurricane expert, said.

Winds gusted to 59 mph at Green Canyon Oil Platform, over the Gulf of Mexico, south of Louisiana this past weekend. The platform is 33 feet above the surface of the Gulf of Mexico.

An AccuWeather Local StormMax™ wind gust of 60 mph is forecast in lieu of any thunderstorms around the Midwest through Wednesday. Gusts could approach 70 mph where thunderstorms are involved. For comparison, hurricane-force winds are 74 mph or greater.

Several tropical systems have traveled into the Midwest over the years, according to the National Weather Service (NWS). Most of these had lost or were losing tropical characteristics while arriving across the region.

Two notable storms to survive the trek into the Midwest, Ike and Gustav, traveled well inland and reached the Midwest during September 2008. Both of these former hurricanes transitioned to non-tropical storms as they moved over the region; however, the impacts of these systems were felt widely.

High winds generated by Ike were especially widespread, deadly and destructive over the interior central United States with more than a dozen people killed, damage in the billions of dollars and millions of utility customers without power at one point. Impact from Gustav was much less severe.

Only a few storms that originated in the tropics in June pushed as far inland as the Midwest in recorded history. Tropical Storm Candy in 1968 and an unnamed tropical storm in 1960 are a couple of noteworthy storms to track into the region this early in the season.

Other dissipating tropical systems have trekked into Wisconsin in the past, although Cristobal could track farther west across Wisconsin than any other post-tropical system on record since the mid-1800s, according to the National Hurricane Center.

A storm, known as the Texas Hurricane from 1949, tracked across southeastern Wisconsin as a post-tropical system during October.